问题 选择题

在一定温度下的定容密闭容器中,下列说法能表明反应:A(s)+2B(g) C(g)+D(g)已达平衡的是

A.混合气体的压强不变

B.消耗2molB的同时生成1molC

C.混合气体的相对分子质量不变

D.气体的总物质的量不变

答案

答案:C

反应前后体积不变,即气体的总物质的量不变,压强恒定。消耗2molB的同时一定生成1molC,所以不能说明。混合气体的相对分子质量是混合气的质量和混合气的物质的量的比值,物质的量不变,但质量是变化的,所以C可以说明。答案是C

单项选择题
阅读理解

第三部分:阅读理解(共20小题;每小题2分,满分40分)

   阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

        Hsieh.a never--say--die young man,has mastered the technique of painting hy holding

   the paintbrush in his mouth.When he was sixteen,Hsieh had a terrible electrical accident.

   Both of his arms and the lower part of his right leg were cut off.He also lost sight in his

   rigllt eye.But Hsieh didn’t lose heart.He decided to learn art,and took the first difficult

    step toward changing his life.

        “At first.I tried to hoht a pen in my mouth.But I couldn’t control it,”Hsieh said,“Fi—nally,after trying over and over again,I learned tO write my OWn name.”

Learning to paint was even more difficuh.At first,every brushstroke he made caused

deep cuts in his mouth.It was ext remely painful.But Hsieh didn’t let the pain discourage

    him.“lnstead,I held the painlbrusb even tighter,”Hsieh explained in a firm voice.“l   

knew if I gave up.it would not only be the end of my painting,hut also the end of my

struggle for a better life.”No matter what the obstacle(障碍)is,Hsieh always manages to

find the bright side of the situation.

  Hsieh works hard tO inspire others.He is a tireless lecturer,giving about four hundred

formal speeches a year!“If a person like me can lead a happy life,”Hsieh explained,“why

would regular people feel unhappy?It doesn’t always take tWO arms tO achieve your dreams.

A11 it lakes is a warm heart.”

56.What happened tO Hsieh when he was young?

    A.He was struck by electricity.

    B.His left leg was hurt.

    C.He lost heart because of failure.

    D.He was ill for two months.

57.Which of the following is his character?

  A.Realistic thought.    B.Impressive works.

  C.Unexpected news.    D.Belief in SUCCESS.

58.Which is right?

    A.Hsieh once got the help from the government.

    B.Only such a person like Hsieh can succeed.

    C.He touched himself before he began to paint.

    D.It doesn’t always take tWO arms to realize one’S dream.

59.Which is the best title of the passage?

  A.How to learn painting.    B.A painter without hands.

  C.A man who was hurt.     D.How to make oneself well—known.